Three Months Ended

Mar. 31,

2012

June 30,

2012

Sept. 30,

2012

Dec. 31,

2012 As revised

Mar. 31,

2013 As revised

June 30,

2013

Sept. 30,

2013

Dec. 31,

2013

(Dollars in thousands, except per share amounts)

Revenues:

Electricity

$

82,247

$

81,882

$

77,612

$

76,057

$

68,298

$

87,713

$

88,994

$

84,742

Product

50,105

44,826

54,685

37,263

50,608

64,966

41,755

46,163

Total revenues

132,352

126,708

132,297

113,320

118,906

152,679

130,749

130,905

Cost of revenues:

Electricity

57,931

56,565

59,924

64,630

55,088

58,641

61,356

57,789

Product

34,627

31,818

42,130

26,771

37,041

43,657

29,637

30,212

Total cost of revenues

92,558

88,383

102,054

91,401

92,129

102,298

90,993

88,001

Gross margin

39,794

38,325

30,243

21,919

26,777

50,381

39,756

42,904

Operating expenses:

Research and development expenses

1,048

1,464

1,436

2,160

1,000

1,608

838

1,519

Selling and marketing expenses

4,922

4,570

3,346

2,966

11,509

3,777

2,575

6,752

General and administrative expenses

7,314

6,757

6,132

7,903

6,584

7,134

6,546

8,924

Impairment charges

—

7,264

229,113

—

Write-off of unsuccessful exploration activities

768

1,151

—

720

—

4,094

Operating income (loss)

25,742

24,383

12,065

(220,943

)

7,684

37,862

29,797

21,615

Other income (expense):

Interest income

388

336

280

197

41

87

742

462

Interest expense, net

(14,878

)

(14,263

)

(15,400

)

(19,528

)

(15,863

)

(17,504

)

(18,459

)

(21,950

)

Foreign currency translation and transaction gains (losses)

14

(1,756

)

615

1,369

1,682

904

1,258

1,241

Impairment of auction rate securities

—

Income attributable to sale of tax benefits

2,517

2,589

2,311

2,710

3,532

5,783

5,027

5,603

Other non-operating income (expense), net

(161

)

286

215

246

1,417

29

137

9

Income (loss), before income taxes and equity in income (losses) of investees

13,622

11,575

86

(235,949

)

(1,507

)

27,161

18,502

6,980

Income tax benefit (provision)

(5,457

)

(3,884

)

(1,088

)

8,321

(4,047

)

(5,780

)

(5,201

)

1,476

Equity in income (losses) of investees

(140

)

(157

)

(1,245

)

(980

)

—

9

(158

)

(101

)

Income (loss) from continuing operations

8,025

7,534

(2,247

)

(228,608

)

(5,554

)

21,390

13,143

8,355

Discontinued operations:

Income from discontinued operations including gain on disposal of ($0, $0, $0, $0, $0, $3,646, $0, and $0, respectively)

—

1,613

2,123

(64

)

831

4,480

—

Income tax provision

—

(425

)

(391

)

(167

)

(251

)

(363

)

—

Total income from discontinued operations

—

1,188

1,732

(231

)

580

4,117

—

Net income (loss)

8,025

8,722

(515

)

(228,839

)

(4,974

)

25,507

13,143

8,355

Net income attributable to noncontrolling interest

(130

)

(81

)

(67

)

(136

)

(85

)

(322

)

(193

)

(193

)

Net income (loss) attributable to the Company's stockholders

$

7,895

$

8,641

$

(582

)

$

(228,975

)

$

(5,059

)

$

25,185

$

12,950

$

8,162

Earnings (loss) per share attributable to the Company's stockholders:

Basic:

Income (loss) from continuing operations

$

0.17

$

0.16

$

(0.05

)

$

(5.03

)

$

(0.12

)

$

0.46

$

0.29

$

0.18

Discontinued operations

—

0.03

0.04

(0.01

)

0.01

0.09

—

Net income (loss)

$

0.17

$

0.19

$

(0.01

)

$

(5.04

)

$

(0.11

)

$

0.55

$

0.29

$

0.18

Diluted:

Income (loss) from continuing operations

$

0.17

$

0.16

$

(0.05

)

$

(5.03

)

$

(0.12

)

$

0.46

$

0.28

$

0.18

Discontinued operations

—

0.03

0.04

(0.01

)

0.01

0.09

—

Net income (loss)

$

0.17

$

0.19

$

(0.01

)

$

(5.04

)

$

(0.11

)

$

0.55

$

0.28

$

0.18

Weighted average number of shares used in computation of earnings (loss) per share attributable to the Company's stockholders:

Basic

45,431

45,438

45,461

Diluted

45,437

45,438

45,431

45,448

45,494

45,610